Senior Shopify / E-commerce Integration Engineer

You will own the integrations between commerce platforms (Shopify, POS, OMS, third-party SaaS) and the data that moves through them for a large replatforming program. The standard is data correctness at the systems-of-record level: orders, inventory and fulfillment must agree across every platform, provably, before and after cutover. This is a long-term, full-time engagement. It is backend integration engineering, not storefront or theme work.

Key Responsibilities:
Build and maintain REST and GraphQL integrations with Shopify, POS, OMS and third-party business applications
Implement OAuth flows, webhook verification and processing, retries, deduplication and error handling for production data flows
Handle the realities of distributed data: duplicate events, out-of-order delivery, partial failures, eventual consistency
Develop new API integrations with enterprise and SaaS platforms as the program expands
Own SQL and BigQuery work wherever integrations require data movement or transformation
Build automated reconciliation checks so systems of record stay in agreement
Troubleshoot production integrations and data quality issues end to end
Requirements:
5+ years of backend engineering focused on API integrations between enterprise or SaaS platforms
Strong Python in production
REST and GraphQL integration experience on both consuming and building sides
OAuth, API authentication, webhooks and robust error handling patterns
Practical command of idempotency, deduplication and reconciliation design
Strong SQL; hands-on data integration or ETL experience
AWS deployment experience with Docker and CI/CD
Fluent English
Minimum 4 hours daily overlap with US Eastern time, full-time availability
Nice to Have:
Google BigQuery
Shopify APIs (Admin GraphQL, webhooks, Fulfillment Orders) or Salesforce Commerce Cloud
POS, OMS, ERP or fulfillment system integration experience
Event-driven integration patterns: queues, event buses, connectors